They have masses of 13 and 14 respectively and are referred to as "carbon-13" and "carbon-14." If two atoms have equal numbers of protons but differing numbers of neutrons, one is said to be an "isotope" of the other.
Carbon-13 and carbon-14 are thus isotopes of carbon-12.
There was also a historical test of a piece of linen performed in 1950 by Willard Libby, the inventor of the dating method.Libby had first started using the dating method in 1946 and the early testing required relatively large samples, so testing on scrolls themselves only became feasible when methods used in the dating process were improved upon. Davies made a request to date a number of scrolls, which led to a series of tests carried out in Zurich on samples from fourteen scrolls.Among these were samples from other sites around the Dead Sea, which contained date indications within the text to supply a control for the carbon dating results. Along with hydrogen, nitrogen, oxygen, phosphorus, and sulfur, carbon is a building block of biochemical molecules ranging from fats, proteins, and carbohydrates to active substances such as hormones.All carbon atoms have a nucleus containing six protons.